连载1：

求m,n的最大公约数
辗转相除法
 #include <stdio.h>

int main(void)
{
         int m;
         int n;
         int r;

         r=0;

        printf("please input m/n");
         scanf("%d",&m);
         printf("please input n/n");
         scanf("%d",&n);

         printf("m=%d/n",m);
         printf("n=%d/n",n);

         /*if m<n exchange m<-->n*/
        if(m<n)
        {
                 r=m;
                m=n;
                 n=r;
                r=0;
        }

         r=m%n;

        while(r!=0)
         {
                 m=n;
                 n=r;
                r=m%n;
        }

         printf("the greatest common divisor is %d/n",n);
}